Goretex, in my opinion, has limted uses, at best. First, by the time the air gets to the goretex layer, it has cooled considerably. goretex needs a good temp variation between the inner layer & outer layer to work. Second, by the time it gets to that layer, how much has already condensed on the insulation itself? It doesnt magically pass by the insulation fibers, without condensing, until it reaches the barrier. Goretex is way overhyped, and hasnt proved worth its cost, to me anyway. Not to say I dont own goretex gear; I own alot of it. But, it is more market hype than reality.
Now, that being said, I DO have a goretex bivy. And, it HAS been 100% weather proof for me. It excelled in this area (freezing rain, I was perfectly fine). However, if the bivy bag wasnt free, I likely would have gone with a different bivy. However, I have yet to use it in warmer weather (above freezing), so, I dont know how it would perform there. My experience, and the experience of others I know & respect, is that goretex works outstanding when the temps are at or below freezing: provided you regulate your core temp via zippers, cuffs, etc. For bags, below freezing, they are great as well. Anything for much above freezing, I have other, lighter jackets, that work wonders, at a third the cost, and with minimal venting. For bag protection, I will simply take a tarp. Pertex treatment on my bags work wonderfully, even after a couple years worth of use. Adding goretex to a bag is unecessary weight, and makes the bag less pliable.